Looks like a NCO cap "upgraded" to officer......
It has all characteristics of a NCO overseas cap ( cockade , the soutache ) , DRK officer caps had a bullion cockade and NO grey soutache , and offcourse aluminum piping in the cap's crown and at the front side panels.....
So this is not an official officer's cap.....

Theo

Here's a NCO's overseas cap according to regulations : cloth cockade , light-grey soutache and the oval DRK cap badge at the left side of the cap

Here's an officer overseas cap acording to regulations : bullion cockade , NO soutache , the oval DRK cap badge at the left side of the cap and silver / aluminum piping in the cap's crown and at the front side panels